The present invention relates to a system and method for assisting lane-keep traveling of a vehicle, and more particularly to a lane-keep assisting system which determines whether a vehicle tends to deviate from a lane according to a vehicle traveling condition on the lane.
Japanese Patent Provisional Publication No. 11-348696 discloses a system for assisting a vehicle to travel along a lane. This system is arranged to generate alarm on the basis of a relative position of the vehicle relative to lane markers.
However, in the case that the vehicle travels along a small-radius corner, the alarm is not generated even if the vehicle is not steered along the corner, and the alarm is generated only when the relative distance between the vehicle and the lane marker becomes smaller than a predetermined value. Further, even when the vehicle is turning a corner along a lane, this known system generates alarm continuously or intermittently according to the small relative distance.
It is therefore an object of the present invention to provide a lane-keep assisting system which accurately detects that the vehicle tends to deviate from a traveling lane.
An aspect according to the present invention resides in a system for assisting a lane-keep traveling of a vehicle. The system comprises a road image detector, a vehicle behavior detector and a controller. The road image detector takes a view ahead of the vehicle. The vehicle behavior detector detects a behavior of the vehicle. The controller is coupled to the road image sensor and the vehicle behavior detector. The controller is arranged to calculate a road shape on the basis of the view taken by the road image detector, to calculate a target turn indicative value indicative of a target turn for reaching the vehicle to a target position, on the basis of the road shape detected, to calculate an actual turn indicative value indicative of an actual turn of the vehicle, and to determine whether the vehicle approaches a lane boundary of a traveling lane, on the basis of the target turn indicative value and the actual turn indicative value.